DE1965656C3 - Circuit arrangement for monitoring teletype lines monitored for quiescent current - Google Patents

Description

The invention relates to a circuit arrangement for monitoring teletype lines monitored for quiescent current on the duration and direction of the current flow by means of a hochohong to the telex line connected transistor switching, depending on from the direction of the current flow either a First binary signal characterizing the direction of the open-circuit current or a first binary signal characterizing the direction of the closed-circuit current, provides a complementary second binary signal

The telegraphy modulation produced by the remote * Character transmission is given And that in μ If there is a sequence of positive or negative moments, the falling back into the idle state must not be allowed effect of the monitoring arrangement. On the other hand, every negative signal of a sufficiently long duration should be the Return to the idle state of the monitoring monitoring Allow order; such a signal corresponds to the end signal (end signal) of the connection. The return the arrangement in the idle state (which is expressed by the absence of a potential at the output) then the chain of participating bodies will be released.

Overwax arrangements are already known, the older of which are electromagnetic relays were educated. However, such relays are subject to rapid wear and tear, require frequent adjustments, have too little delay margin in certain modulation cases (32nd combination) large manufacturing variance from one Exeuplar to another and above all do not allow for fast Adapt modulation speeds above 50 baud.

Another monitoring arrangement described in French patent 14 05 994 brought about a major advance in electromagnetic relays; however, requires their commissioning an external voltage source with_20 kHz as well as a setting in the course of monitoring due to the dispersion of the manufacturing characteristic wire Tori-Weher is a circuit arrangement from DE-AS 1090252 known in which the monitoring of the teletype line via a time delay element occurs Because of this time delay, this circuit arrangement is not capable of a transition to quickly display the line in the working state.

In principle, a circuit connection is constructed in a similar manner, which is described in DE-AS Π 90 023 and the change in Stromrichtuiig on the line after a indicated delay.

Also described in DE-AS 122523t Circuit arrangements for monitoring a Fernscfareibleinmg are not able to move quickly due to the delay elements provided in the signal train to respond to the transition to the working state.

The object of the invention is therefore to provide a circuit arrangement that quickly reacts to the transition Telegraph line reacts in the working state and others set brief interruptions in this state * due to the transmitted "Fcm write signals disregarded

This object is achieved by the preferred arrangement defined in the main claim Embodiments of the invention are described in the subclaims.

The device according to the invention can be placed at any point of the telegraphic channel especially in the self-connecting telegraphic connection circuit or in a teleprinter control box or any other place that monitors the state of a telegraphic channel The connection circle is the organ which, controlled by the recording device, establishes a connection between the caller and the called party The callee's choice is checked, his category is checked and his callsign is allowed to pass the caller has checked the connection between the Caller and the called party controls a quiescent current, which causes the commissioning of the monitoring device causes

The invention is illustrated below with reference to Drawing described for example.

In the exemplary embodiment shown, the detector circuit of the device according to the invention consists essentially of the transistors Tt, TEC and Tl-, Ti and Tl are known transistors of the pnp type, and the transistor TEC is a field effect transistor. Of the

The delay circuit consists essentially of the transistors Γ3, 74 and 7 * 5 of the pnp type and a delay circuit which comprises a capacitor C and a resistor R10

In the case of the telegraphy line wire LT, it is assumed that the FC side is connected to a signal transmitting device and the SC side is connected to a signal receiving device, for example a teleprinter

A diode D 1 in series with the lead wire, the continuity or continuity of the channel in the ι ο emitting negative moments is guaranteed by its cathode to EC and with its anode to SC directed towards to the terminals of the diode D, a resistor R 1 Sufficiently small size arranged in the branch or in the shunt, the end of which is connected on the side of the cathode of Dl to the emitter of the transistor Tl and whose end on the side of the anode of Dl is connected to the base of the transistor TX The resistor ensures a minimal triggering -Threshold. to avoid zo that the apparatus through. Interference currents is influenced. The collector of the transistor 7 * 1 fet is connected via a resistor R 2 to the gate (grid) g of a field effect transistor 7BC, which in turn is connected to the negative polarity via a resistor A3. The source electrode s of 7EC is at a common point with a resistor R 4, the other end of which has a connection with negative polarity and is connected to a Zener diode ZTVt, whose other terminal, the cathode, has a positive polarity connection to the drain d of TEC is connected via a resistor RS to the base of a transistor TI , which in turn is connected to the positive polarity via a resistor R 6. The emitter of TZ is dhxks connected to the κ positive polarity and its collector is at a common point of three circuit branches : the first branch connects it via a diode D 2 to the base of a transistor 7 * 3, the second branch connects it to the HiUV or w additional output 5a via a diode D6 and the third branch connects it to the output via a diode DJ S of the device; according to the invention, wherein the diodes D2, D6 and DT are aligned such that their anode is connected to the collector of ΤΊ The base of the transistor 73 is also on the one hand with the emitter of 7 * 3 via the protective diode D3 and on the other hand via a Resistor R 8 associated with the negative polarity; D 3 is oriented in such a way that its anode is connected to the base of 7 * 3. The emitter of Γ3 is also on the one hand with negative polarity via a resistor RT and on the other hand via a Zener diode ZN 2 and a diode D4 in series with a common point N connected, the diodes ZN2 and D4 being oriented such that their cathode lies on a common point. A branch Λ / on the connection between the diode DA and the point N can receive a positive polarity either directly or via one or more & o contacts the fact of allowing the passage through one or more contacts with the aim of avoiding the influence on the device of volatile positive pulses on the graphical channel. Is used in the description of the operation t assumed> 5 that a positive polarity is connected directly to the point M Dar collector of transistor T3 is on the one hand via a resistor R9 to the negative polarity and the other with the upper plate of the capacitor C compound. The lower assignment of the same capacitor C is connected directly to the base of a transistor 7 * 4; it is also connected to the negative polarity with respect to R 9 via a resistor R 10 of large value. The emitter of transistor 7 * 4 is connected to point N via a protective diode D 5 which is oriented so that its cathode in Connection with the emitter is the collector of TA is in direct connection with the base of a transistor TS, which also has a resistor R Il with a negative polarity connection. The collector of TS is connected to the output S via a diode D 8, which is aligned so that its anode is connected to the collector.The emitter of the transistor T5 is on the one hand via a resistor R 12 with the negative polarity and on the other hand via a resistor R 12 with the negative polarity and on the other hand with the common point M via a Zener diode ZN 3 connected, which is oriented in such a way that its anode is connected to the emitter of the Transiii'rs TS

Before describing how the Apparatus according to the invention is given some explanations relating to the telegraph operation (assume a network of type A)

- an available line is characterized or marked by a negative current

- the call signal appears when a positive current replaced the negative current

- the final signal is shown by the return of the Line to negative current.

The negative currents that make up the modulation, during which the device is to provide a control potential at the output, of course, must be of the permanent negative current can be distinguished, which forms the release signal aa the end of which Device no control potential at the output tnyhr deliver sotL

The distinction is made by measuring the value of the negative currents. With automatic Transmission (modulation with seven elements per character with 50 bands) is a borderline case, we know it around the »32. Combination «acts; the 32nd combination actually includes a negative start followed by five negative moments and then the positive stop; which corresponds to 120 ms of the negative signal and 20 ms of the positive signal a certain deformation of the signals (40% distortion on the start) can be present as the most unfavorable value in the transmission of a 32nd combination allow the ratio 128/12, i.e. 128 ms (t? S negative signal for 12 ms of the positive Signal. The device according to the invention should continue to apply a control potential at the output of this Borderline to deliver.

The device according to the invention gives when operating at 200 baud for the unfavorable borderline case Ratio 32/3 in the case of application of the telegraphic alphabet No. 2.

The mode of operation of the device according to the invention is as follows as possible examined:

- in the case of a pcimanetite negative current on the line,

- in the case of a permanent positive current on the line,

- in the full of modulation,

- in the case of release.

Permanent negative current on the line

Since the diode Dl is oriented in the forward direction, the potential of the emitter of the transistor Ti is almost exactly the same as that of the base. The transistor Ti is blocked. Under these conditions, the gate (gatt) g of the field effect transistor TEC is at the potential - e of the battery, while the source s, which is connected to that of the resistor RA and the Zener diode ZN i .deten voltage parts is connected to a small, negative potential (thus source 5 with respect to gate g) ; therefore the transistor TEC is blocked. The transistor T2 is also blocked, because its emitter ι πα its base are on the same Potcntia + e If a positive potential arrives directly on the wire M , the transistors Ti and TA are id, because the potential of the emitter is higher than that which is Elase.i; the transistor 7 "5, however, remains blocked. Thus, no control potential appears either at the output Sa or at the output S. The capacitor C is discharged.

Permanent positive current on the line

The diode Di is blocked for the positive current coming from EC on the line; the potential of the emitter of Π is higher than that of the base, as again closes a circuit through the resistor R 1 and the ground via SC Thus, the transistor Ti leitend- The gate g of the transistor TEC assumes a high positive potential, since the resistance R 2 is less than R 3; thus the transistor TEC is conductive (the source s negative in benjgj? on the gate g). As a result, a circuit is formed across the voltage divider R AIZN I, the transistor 7FCUn (I the resistors RS and R 6, which has the result that the potential of the base of the transistor T2 is made negative with respect to the potential + e of the emitter. The transistor 7 "2 is in turn conductive and supplies a current or a positive potential to the outputs Ss and S of the device via the diodes D 6 and DJ . The emitter of the transistor Γ3 is with the positive polarity of the point M via the diodes ZN 2 and dA connected the other hand, sets the transistor Ti is the positive polarity (+ e) to the base of the transistor T3 via diode D2;.! since the transistor consequently has T3 a higher potential at its base than at its emitter will be blocked. The transistor TA is conductive because the positive polarity of the wire M is applied to its emitter via the diode D 5 while its base is at the negative potential via d <η resistor R 10. Since TA is conductive spe He nt the transistor Γ5 in the same way as was seen in the previous case. The capacitor C can be based on the negative polarity via R 9 on its upper assignment and due to the positive polarity received on the emitter of TA on the lower assignment via the emitter-base connection.

Upon receipt of a positive signal on the line hm, the outputs Sa and S thus immediately supply a positive potential via the diodes D 8 and D 7, respectively.

Modulation on the line

If the line is under> Call due to the fact that there is a positive telegraphic signal on the line, the appearance of the negative start of a combination causes the transistors Ti. TEC and 7 "2 to be blocked (see the case of the permanent negative current on the line The positive polarity applied to wire M makes transistor Γ3

in conductive, since its base becomes negative with respect to its emitter via the resistor R 8, and the diode D 3 blocks. The transistor 7 * 3 applies a positive potential to the upper assignment of the capacitor Can, which is connected to the negative polarity via the resistor R9

Γ »is. The capacitor Centladt moves into the resistor R 10 while maintaining a positive voltage in relation to the supply voltage -te during the entire discharge time on the lower assignment; the duration of the discharge is a function of the

-Ii time constants formed by the resistance η iö and the capacitance C. In addition, this strong positive potential of the lower occupancy of C blocks transistor TA. since the potential of its base is higher than the potential of its emitter The

2i transistor 7 "5, which was blocked, becomes conductive (negative

Base with respect to the emitter) and delivers a positive Potential across the single output 5, since the diode D 7

blocks opposite the output Ss

W 3τιη the first characteristic moment is positive,

χι Ti, TEC, T2 are conductive again, and the outputs 5a and S are at positive potential; T3 blocks, TA becomes conductive again and capacitor C charges. Γ5 is blocked by TA. The output 5 remains consistently positive.

Ji If the first characteristic moment is negative, the state given by the arrival of the start continues as long as the capacitor C maintains a blocking potential on TA . The time constant is provided so that TA remains blocked during the unfavorable limit time, i.e. for at least 128 ms (actually 350 ms).

The circuit is maintained during the modulation due to the charges and discharges of the capacitor C, whereby the charge via the resistor R 9 (of a smaller value compared to R 10) is of a much shorter duration than the discharge via the resistor R 10.

release

A negative release signal that suddenly appears on the telegraphic line after a positive signal causes the monitoring relay connected via output S to drop out after the delay given by the time constant of the device has been exhausted.

In fact, as before, the transistors Ti, TEC and TZ block. The transistor TZ becomes conductive and causes the capacitor C Der to discharge

wi transistor TA blocks, and T5 becomes conductive and keeps the positive polarity on the wire 5 upright Meanwhile, the transistor TA, when the time on the line exceeds the negative signal, the discharge time of the capacitor blocked by the TA

t> 5, conductive again as soon as the potential of its emitter is again higher than that of its base TA then blocks

Polarity more, neither through the output of T2

(blocked) still through the output of 7 "5 (blocked). The drop-out of the monitoring relay is thus controlled. A separation on the line from any Duration with negative current on the line would be the

produce the same effects as the device only through positive currents are ignited on the line.

The operating mode can also be summarized in the following table:

In operation
nc; <"nene elements - permanent + permanent modulation + release
350 ms ago after 350 ms Transistor 7Ί locked conductive locked conductive locked locked Transistor TEC locked conductive locked conductive locked locked Transistor Tl locked conductive locked conductive locked locked Transistor T3 conductive locked conductive locked conductive conductive Transistor T4 conductive conductive locked conductive locked conductive Transistor Γ5 locked locked conductive locked conductive locked cioh laHpnH «Irh pnl- «I again- ent unload laciend ladcnd loading Exit Sat. no tax
signal Control signal no tax
signal Control signal no tax
signal no tax
signal Exit S. no tax
signal Control signal Control signal Control signal Control signal no tax
signal

Likewise, in a device according to the invention, transistors of the opposite type can be used or the diodes can be used together by reversing the supply connections be reversed.

In the device according to the invention there is

Possibility to modify the time constant by choosing the values of C and R 10.

Finally, the device according to the invention can be used in connection with any type of network that defined by the CCITT.

1 sheet of drawings

909 615/71

Claims (3)

Claims; 1. Circuit arrangement for monitoring shut-down telegraph lines for ϊ duration and direction of the current flow by means of a high-ear transistor switch connected to the teletype line, which, depending on the direction of the current flow, either a first binary signal characterizing the operating current direction or a complementary characterizing the quiescent current direction provides a second binary signal, characterized in that a further transit gate switch (T3, TA, T5) connected downstream of the transistor switch (TX, TEQ T2) at the beginning of the quiescent current direction (neg.) immediately sends a binary signal ("L") to a also connected to the output of the OR gate connected to the transistor switch (D7, D *} passes and that in the further transistor switch (f7 * 3, TA, 7 * 5) provided delay switching means (R% Rib, C) limit the duration of this binary signal so that it lasts longer than that longest expected telegraph characters (combination no. 32) on the telex line ung, the OR gate supplies a binary signal to an output (S) of the circuit arrangement when either the first transistor switch (Tl, TEQ Γ2) or the second transistor switch (Γ3, Γ4, T5) supplies the binary signal. 2. Circuit arrangement according to spoke! “Characterized in that the first transistor switch contains a diode (D t) which is inserted in the line and the egg« i low resistance ^ Rl) and the Eroitterbasiss £; ecfce eloes first transistor (Tt ) are connected in parallel ¹ , and that the collector circuit of this transistor controls a field effect transistor (TEC) , which in turn is followed by a transistor (T2) in emitter base configuration. 3. Circuit arrangement according to one of claims 1 or 2, characterized in that the coupling between the two transistor switches is carried out by a diode (DTt) and the OR element at the output (S) of the circuit arrangement also has two diodes (DT, £> 8 ) contains 45